Optical imaging pen having a force sensor

Abstract

Provided is an optical imaging pen configured to detect information encoded with infrared ink on a page. The pen includes a housing with an ink pen cartridge and a stylus. The ink cartridge and stylus are configured to be individually brought forward through an open end of the housing by rotation of a pen top rotatably mounted on an end of the housing. The pen also includes an infrared LED inside the housing for providing infrared radiation for projection onto the page, and an image sensor for receiving reflected radiation from the surface. Also included is a radio frequency circuit having a radio frequency (RF) transmitter and receiver, and a controller for controlling operation of the LED, sensor and radio frequency circuits. The controller includes a force sensor configured to detect displacement of the stylus or cartridge to enable a determination of a force being applied to a nib of either the cartridge or stylus.

1. An optical imaging pen configured to detect information encoded with infrared ink on a page, said pen comprising:
 a housing; 
 an ink pen cartridge and a stylus mounted in the housing, the ink cartridge and stylus configured to be individually brought forward through an open end of the housing by rotation of a pen top rotatably mounted on an end of the housing; 
 an infrared LED inside the housing for providing infrared radiation for projection onto the page; 
 an image sensor for receiving reflected radiation from the surface; 
 a radio frequency circuit having a radio frequency (RF) transmitter and receiver; and 
 a controller for controlling operation of the LED, sensor and radio frequency circuits, the controller having a force sensor configured to detect displacement of the stylus or cartridge to enable a determination of a force being applied to the nib and the cartridge. 
 
     
     
       2. The optical imaging pen of  claim 1 , wherein a rotatable cam barrel is secured to the pen top, the cam barrel including a cam in the form of a slot defined in walls of the cam barrel for engaging cam followers in the form of projecting slider blocks of the pen cartridge and stylus, wherein rotation of the pen top slides one of the pen cartridge and stylus into and out of the housing. 
     
     
       3. The optical imaging pen of  claim 1 , which includes a rechargeable battery mounted about, and in contact with, an electronics chassis of the controller with an induction coil mounted about the chassis to enable induction recharging of the battery. 
     
     
       4. The optical imaging pen of  claim 3 , wherein the force sensor is configured to detect light from the infrared LED via reflectors mounted on the slider blocks. 
     
     
       5. The optical imaging pen of  claim 1 , having a radio antenna mounted within the housing, said antenna in signal communication with the radio frequency transmitter and receiver. 
     
     
       6. The optical imaging pen of  claim 1 , wherein the controller includes an orientation sensor which is configured to facilitate calculation of an orientation of the pen. 
     
     
       7. The optical imaging pen of  claim 1 , having a pair of orthogonal accelerometers mounted in a normal plane of the pen axis, said accelerometers allowing the pen to sense motion.